ECE2021 Oral Communications Oral Communications 11: Adrenal and Cardiovascular Endocrinoloyg (6 abstracts)
1Internal Medicine, Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Italy; 2University of Würzburg, Würzburg, Germany; 3Rare cancer Network COMETE cancer, Hôpital Cochin, Paris, France; 4Division of Endocrinology, Department of Medicine, CHUM, Montréal, Canada; 5Department of Endocrinology University Hospital Zagreb, Zagreb, Croatia; 6Department of Internal Medicine, Maxima Medisch Centrum, Eindhoven, Netherlands; 7University of Birmingham, Birmingham, Northern Ireland; 8Niguarda Ca Granda Hospital, Milan, Italy; 9Centre Hospitalier Universitaire de Reims, Service dEndocrinologie – Diabète – Nutrition, Reims, France; 10HospicesCivils de Lyon and University de Lyon, Lyon, France; 11Division of Endocrinology, Metabolism and Nutrition, Mayo Clinic, Rochester, United States; 12Endocrinology in Charlottenburg, Berlin, Germany; 13Serviço de Endocrinologia e Metabologia, ICESP, Universidade de São Paulo, São Paulo, Brazil; 14Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy; 15Endocrine Oncology Gustave Roussy, Villejuif, France; 16Statistical Unit, Department of Clinical and Biological Sciences, University of Turin, San Luigi Hospital, Orbassano, Italy; 17Department of Endocrinology, Medizinische Klinikund Poliklinik IV, Klinikum der Universität München, Munich, Germany; 18Service dEndocrinologie, Hôpital Cochin, Paris, France; 19Oncology Unit, Department of Medicaland Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, ASST Spedali Civili di Brescia, Brescia, Italy
Background
The ESE-ENSAT guidelines suggest adjuvant mitotane for patients with adrenocortical carcinoma (ACC) at high risk of recurrence following radical surgery. This indication has a limited evidence base, lacking results from randomized controlled trials. No suggestion is available in low-risk patients, since studies did not stratify patients for prognosis. The randomized controlled study ADIUVO compared the efficacy of adjuvant mitotane (MIT) treatment vs. observation (OBS) in prolonging recurrence-free survival (RFS) in patients at low-intermediate risk of recurrence.
Methods
The main inclusion criteria were: stage I-III ACC, R0 surgery, and Ki-67 ≤10%. Patients were randomly assigned 1:1 to MIT or OBS. The primary endpoint of the study was RFS. Patients who refused randomization were eligible for the ADIUVO OBSERVATIONAL study. In this prospective, observational study, patients were managed as in ADIUVO except for randomization. A total of 91 patients were enrolled in ADIUVO, 45 in the MIT and 46 in the OBS arm. Baseline characteristics of patients were perfectly matched between the 2 arms: median age, 51 vs. 50.5 years; female, 73% vs 67%; stage I, 20% vs 26%; stage II, 67% vs 63%, stage III, 13% vs 11%; ACC secretion 44% vs 36%; Weiss 5 vs 5; respectively. In ADIUVO OBSERVATIONAL, 42 patients were treated with mitotane and 53 were untreated. Baseline characteristics of patients were matched between the 2 groups and with MIT and OBS groups in ADIUVO. Thus, the ADIUVO OBSERVATIONAL cohort was analyzed in parallel to deal with the difficult recruitment in ADIUVO.
Results
In the ADIUVO study, recurrences were 8 in the MIT and 11 in the OBS arm, while deaths were 2 and 5, respectively. RFS and overall survival (OS) did not significantly differ between the 2 arms. Tumor size was a predictor of RFS in multivariable analysis. In the OBS arm, the HR for recurrence was 1.321 (95% CI, 0.55–3.32, P = 0.54) and HR for death 2.171 (95% CI, 0.52–12.12, P = 0.29). The survival analysis in the ADIUVO OBSERVATIONAL study confirmed that of ADIUVO. Given the outcome of both studies, the NNT is 55.
Conclusions
ACC patients at low-intermediate risk of recurrence show a rather good prognosis (5-yr RFS of 75%) and do not benefit significantly from adjuvant mitotane. The results of the ADIUVO study do not support routine use of adjuvant mitotane in this subset of patients, who may thus avoid a potentially toxic treatment. This is an important step toward personalization of ACC care.